Help to Archer C2 V1 EU Unbrick

Installing and Using OpenWrt
1

Hi,

I accidentally installed the sysupgrade image directly while installing OpenWRT.
Now the U-boot method does not work.
I have the hardware for UART install.
But couldn't find the exact instructions for this model.

Please help.

Thanks,
Subhajit

2

if you have serial, interrupt uboot, and post the output of the help command, and perhaps the u-boot menu too.

3

Will u boot even load?
I installed the sysupgrade directly. I am unable to trigger uboot firmware install with reset and power button any more.

4

you're right, it was probably overwritten by the image missing the uboot part.

RIP

5

There is no way to install any firmware, now?

6

There should be an SPI option. Is there any way to get u-boot to install in the flash directly? From there I should be able follow the instructions?

7

Remove the flash chip from the router and mount it on a SPI programmer. The last 64 kB of the chip is unit specific radio data, and not replaceable any other way, so be sure to read the whole chip and save the contents in a safe place. As a last resort, the radio data could be reinstalled at runtime with kmod-mtd-rw if the next step of writing to the chip corrupts it. I don't think that your flashing the wrong file would have affected the radio data, yet. The other partitions at the end of the chip likely contain the factory MAC address etc.

Then extract the bootloader image from stock firmware as described on the wiki page, and concat it to a sysupgrade firmware, and write this image to the flash chip, being careful that the last 256 kB does not get erased or overwritten. Put the flash chip back in the router.

8

Hi mk,
How do I make sure that last 256kb is untouched?
Can you help me with specific command that i can use from a linux system, connected via cp2102?

Thanks

9

You will need a SPI programmer typically using a CH341 chip. The Linux program flashrom is the most common way to control these programmers.

10

Yes, but any specific parameter to avoid last 256kib? or in general any specific command for this device?

11

I wouldn't know; it's been a long time since I last used flashrom. The important thing is to make sure you have a good read of the whole chip stored on your PC before trying to write anything.

12

Sure, thanks